Rochester Optical Co. (Rochester, NY)
R.O.C. Single (single achromat) View Lens, Variation 1 (Waterhouse stop slot) - c. 1880s-c.1890's
Illustrated Catalogue of
Photographic Apparatus, C.H. Codman & Co. (Boston, MA), June 1886,
p. 25
Notes:
Rochester Optical's Single View Lens is a single achromat (hence the name). Having only two elements in one group in the rear of the lens, it was the most inexpensive lens offered in their catalogs.
Early in its run, Waterhouse stops were provided in threes, conveniently riveted together. This type of lens is referred to here as the R.O.C. Single View Lens, Waterhouse Stop Slot. In this state, the lens appears to be very amateurish: the stop slot was cut after assembly, and sometimes crooked or not of uniform width; the thick nickel plating often couldn't cover the uneven soldering.
Later in its run, the lens came in brass with a rotating wheel having five stops (one of which is essentially open or full diameter, as shown in the engraving above. Brass Single View lenses appear to have been more neatly made than its Ni-plated brethren. This type of lens is referred to here as the R.O.C. Single View Lens, Rotating Stops.
References:
Illustrated Catalogue of Photographic Apparatus,
C.H. Codman & Co. (Boston, MA), June 1886, p. 25
